Bridging song and behavior: Linking humpback whale song characteristics to the behavior of singers in Hawai`i

Two approaches, at times divergent, have informed our understanding of humpback whale song. Acoustic analyses have described its occurrence, structure, and dynamics, while field observations have revealed a behavioral context. In 2006, we proposed a hypothesis that potentially accounts for both the complex, collectively changing song and the ubiquitous song-mediated interactions with other males during the breeding season. The hypothesis proposed that the degree of song similarity reflects the association history of individual males: the more recently they have associated, the more similar their songs. Since then, different lines of research have tested predictions derived from this hypothesis. These include comparisons of song composition and dynamics across North Pacific breeding assemblages and playback experiments designed to test whether singers respond differently to similar versus dissimilar songs. Results have been consistent with the hypothesis, though key questions remain including why humpback males might benefit from recognizing recent associates during the breeding season.